Emulsion and Soft Colloid Transport in Porous Media and Confined Systems

乳化液滴是软胶体的实例。油-水乳液通常存在于油田应用中的采出水中。这些乳液在采出水的处理中提出了许多挑战，其中人们试图使油和水不稳定并将其分离成两相。相反，乳液和软胶体用于几种工艺工程应用中，即使在剪切力或其他不稳定力的影响下，它们也需要保持稳定。我们建议的研究重点是在电场和/或压力的影响下，这种乳液或可变形胶体在高度狭窄的通道或孔隙中的流动。在这种流动期间，液滴可以在剪切力和电力的影响下变形和破裂或聚结。此外，收缩通道的壁可以对这些乳液液滴施加力。拟议的研究的短期目标是发展的各种电气，流体动力学和胶体影响的流动，变形和稳定性的乳液液滴和可变形的胶体的机制的理解。这里提出的理论建模研究将建立在我们过去的经验，在模拟胶体运输，薄膜排水，和电强迫下的液滴变形。这些模型将采用流体流动、电场和带电物质分布的控制方程来确定液滴或软颗粒的流动性。随后，这些模型将被纳入宏观胶体传输模型预测宏观运输行为的乳液或软胶体分散体通过一个填充床的收集器。各种理论模型将通过与适当设计的微流体和柱色谱实验的结果进行比较来验证。研究成果预计将提供一个基本的机械理解的相关模式的乳状液在多孔介质中的运输，并将有助于开发更有效的技术，过滤，破乳，浮选，分离，并最终，生产水处理。 9名研究生将通过该计划接受培训。

Emulsion droplets are examples of soft colloids. Oil-water emulsions are commonly found in produced water in oil field applications. These emulsions pose numerous challenges in treatment of produced water, where one attempts to destabilize and separate the oil and water into two phases. Conversely, emulsions and soft colloids are used in several process engineering applications where they need to remain stable even under the influence of shear or other destabilizing forces. Our proposed research focuses on the flow of such emulsions or deformable colloids in highly constricted channels or pores under the influence of electric field and/or pressure. The droplets can deform and break, or coalesce under the influence of shear and electrical forces during such flows. Furthermore, the walls of the constricted channels can impose forces on these emulsion droplets. The short-term objectives of the proposed research are to develop mechanistic understanding of the various electrical, fluid dynamic, and colloidal effects influencing the flow, deformation, and stability of emulsion droplets and deformable colloids. The theoretical modeling studies proposed here will build on our past experience in modeling colloid transport, thin film drainage, and droplet deformation under electrical forcing. These models will employ the governing equations of fluid flow, electric fields, and charged species distribution to determine the mobility of the droplets or soft particles. Subsequently, these models will be incorporated into a macroscopic colloid transport model to predict the macroscopic transport behavior of the emulsion or soft colloidal dispersion through a packed bed of collectors. The various theoretical models will be validated by comparing their results against suitably designed microfluidic and column chromatography experiments. The research outcomes are expected to provide a fundamental mechanistic understanding of the pertinent modes of emulsion transport in porous media, and will help develop more efficient techniques for filtration, de-emulsification, flotation, separation, and ultimately, produced water treatment. Nine graduate students will be trained through this program.